Heat rejection system for electrochemical climate control system
A climate control system includes an electrochemical device in fluid communication with at least one fluid conduit that also includes a first heat exchanger, an expansion device, and a pump, but may be free of any condensers. A working fluid is circulated in the fluid conduit that has a composition that undergoes a reversible hydrogenation and dehydrogenation reaction when it passes through the electrochemical device when a potential is applied thereto. The climate control system includes a heat rejection system in the form of a recirculation loop having a second heat exchanger configured to cool a portion of the working fluid exiting the electrochemical device and a recirculation pump that circulates the portion of the working fluid exiting the electrochemical device through the second heat exchanger and back to an inlet of the electrochemical device. Methods for rejecting heat from an electrochemical climate control system are also provided.
1. A climate control system comprising:
an electrochemical device;
a first heat exchanger configured to operate as an evaporator and disposed upstream of the electrochemical device;
an expansion device disposed between the electrochemical device and the first heat exchanger;
a first pump;
a fluid conduit for establishing fluid communication between the electrochemical device, the first heat exchanger, the expansion device, and the first pump, so that the first pump circulates a working fluid in the fluid conduit, wherein the working fluid has a composition that undergoes a reversible hydrogenation and dehydrogenation reaction when it passes through the electrochemical device when a potential is applied thereto; and
a heat rejection system configured to cool a portion of the working fluid exiting the electrochemical device for heat rejection from the electrochemical device.
2. The climate control system of claim 1 , wherein the electrochemical device comprises a positive electrode, a negative electrode, a separator, and a first outlet, wherein the inlet is a first inlet and the electrochemical device further comprises a second inlet, wherein the working fluid exiting the expansion device in a gas or vapor phase enters the positive electrode in the electrochemical device via the second inlet and a portion of the working fluid cooled in the heat rejection system is in a liquid phase and enters the positive electrode in the electrochemical device via the first inlet.
3. The climate control system of claim 1 , wherein a temperature of the working fluid is reduced by greater than or equal to about 5° C. after exiting the heat rejection system as compared to an inlet temperature into the heat rejection system.
4. The climate control system of claim 1 , wherein a temperature of the working fluid is reduced by greater than or equal to about 18° C. after exiting the heat rejection system as compared to an inlet temperature into the heat rejection system.
5. The climate control system of claim 1 , wherein a temperature of the working fluid entering the electrochemical device is maintained at a temperature of less than or equal to about 100° C.
6. The climate control system of claim 1 , wherein a percentage of recirculation of the portion of the working fluid in the heat rejection system is greater than or equal to about 2% and less than or equal to about 90% by volume of a total volume of the working fluid entering the electrochemical device.
7. The climate control system of claim 1 , wherein composition comprises acetone in a dehydrogenated form and isopropanol in a hydrogenated form.
8. A method for rejecting heat from an electrochemical climate control system comprising:
circulating a working fluid in a fluid conduit that comprises a first heat exchanger configured to operate as an evaporator disposed upstream of an electrochemical device, and an expansion device disposed between the electrochemical device and the first heat exchanger, wherein the working fluid comprises a composition that undergoes a reversible hydrogenation and dehydrogenation reaction when it passes through the electrochemical device when a potential is applied thereto; and
circulating a portion of the working fluid exiting the electrochemical device into a heat rejection system comprising a recirculation loop that cools a portion of the working fluid and rejects heat from the electrochemical device.
9. The method of claim 8 , wherein the working fluid comprises a pair of a first hydrogenated compound and a second dehydrogenated compound that undergoes a reversible hydrogenation and dehydrogenation reaction in the electrochemical device when a potential is applied thereto.
10. The method of claim 9 , wherein the first hydrogenated compound comprises isopropanol and the second dehydrogenated compound comprises acetone.
11. The method of claim 8 , wherein the heat rejection system comprises a second heat exchanger and the method further comprises circulating the portion of the working fluid exiting the electrochemical device through a second heat exchanger in the heat rejection system and back to an inlet of the electrochemical device.
12. The method of claim 8 , wherein a temperature of the working fluid is reduced by greater than or equal to about 5° C. after exiting the heat rejection system as compared to an inlet temperature into the heat rejection system.
13. The method of claim 8 , wherein a temperature of the working fluid is reduced by greater than or equal to about 18° C. after exiting the heat rejection system in the heat rejection system as compared to an inlet temperature into the heat rejection system.
14. The method of claim 8 , wherein a percentage of recirculation of the portion of the working fluid is greater than or equal to about 2% and less than or equal to about 90% by volume of a total volume of the working fluid entering the electrochemical device.